Jump to content


Photo

So What Happens When Your Air Brakes Fail?


  • This topic is locked This topic is locked
19 replies to this topic

#1 Bluenoser

Bluenoser

    Major Contributor

  • Validated Members
  • 604 posts
  • SKP#:104866

Posted 17 January 2012 - 09:06 AM

As a fairly new HDT owner, I have learned a lot about the checks we are supposed to do for our air brake systems. But it would be great to hear from someone that actually experienced a brake system failure. Any stories from the road out there?
2001 34N Pace Arrow Vision V10
2003 International 9200i 500hp ISX Freedomline 12sp
Conversion by 2L Custom Trucks
8kw QD Onan Genset/TS2BLH Hitch
Travel Supreme CL38SLQ1


Posted Image

#2 Darryl&Rita

Darryl&Rita

    Major Contributor

  • Validated Members
  • 1682 posts

Posted 17 January 2012 - 09:42 AM

Depends on source of failure. An air compressor/govenor failure will result in a slow loss of air pressure, along with a warning buzzer. We lost the govenor this past summer, and had plenty of time to diagnose and find parts. A leaking hose could act similarly. A broken hose will likely result in the same air pressure symptoms, but the wheel(s) downstream of the break will likely lock up. A seized s-cam, or broken spring, or shoes stuck from parking to long will give a similar locked wheel(s).

Veni, Vidi, Velcro
I came, I saw, I stuck around

2000 Kenworth T 2000 w/N-14 and 10 speed Gen1 Autoshift, deck built by Star Fabrication
2006 smart fourtwo cdi cabriolet
2007 32.5' Fleetwood Quantum


Please e-mail us here


#3 John (C-IL)

John (C-IL)

    Major Contributor

  • Validated Members
  • 1069 posts

Posted 17 January 2012 - 09:45 AM

If you are talking about air system failure, you stop pretty fast. Had a glad hand come off once and there was a lot of blue tire smoke and 4 really dark stripes on the pavement.

If you are talking over heated, you just keep going and going and going, kinda like the energizer bunny.
1993 Freightliner Conversion; 3176 CAT; Eaton 10spdOD; 120" sleeper; 243"wb.

http://community.web...om/user/JohnCIL

#4 Softail

Softail

    Major Contributor

  • Validated Members
  • 551 posts

Posted 17 January 2012 - 09:57 AM

If you are talking about air system failure, you stop pretty fast. Had a glad hand come off once and there was a lot of blue tire smoke and 4 really dark stripes on the pavement.



I've seen the evidence of this many times. Two DARK black marks begin abruptly in a lane and end on the shoulderPosted Image

If you are talking over heated, you just keep going and going and going, kinda like the energizer bunny.


Had this one happen to me once when I drove commercially in the 80s. Coming off a pass in WV, or MD i think. I was loaded right @ 80,000# with potatoes and hit 13 miles of 6% grade in the dark. A real seat pincherPosted Image A driver I passed came on the CB and said my brakes were all glowing a nice shade of salmon....



Choosing an HDT is similar to many things in life. The options are: good, cheap, and easy. Pick two.
"Hulk Smash Puny Mountain" : 2000 Freightliner Century -Cummins N14+ 460HP, 13 speed, 3.58 rears -Work in progress
2004 Fleetwood Terry Quantum 38'

Posted Image

#5 richfaa

richfaa

    Major Contributor

  • Validated Members
  • 4362 posts

Posted 17 January 2012 - 10:16 AM

Loss of pressure results in a lock up and a drop your socks stop. Slow loss results in a warning buzzer.
Helen and I are long timers ..08 F-350 Ford,LB,CC,6.4L,4X4, Dually,4:10 diff dragging around a 2013 Montana 3402 Big Sky
SKP 100137. North Ridgeville, Ohio in the summer, sort of and where ever it is warm in the winter.

#6 blizzardND

blizzardND

    Major Contributor

  • Validated Members
  • 959 posts
  • SKP#:103674

Posted 17 January 2012 - 10:45 AM

Loss of pressure results in a lock up and a drop your socks stop. Slow loss results in a warning buzzer.

my example;
North Dakota 1983 Day before Christmas eve, -39 degrees, below -100 with the 15-20 mph wind, Ford Louisville single axle mobile home toter,

Air junction box froze up after 10 miles, buzzer starts buzzzing, start slowing down before truck rear axle locks up, pull over, put on 2 beanies (mine and Dads) light butane torch inside cab, gt out, pop open hood, heat junction box carefully so you don't melt plastic lines. Watch dad for thumbs up, jump back into truck, air building up -good! drive down the road pulling 14 x 70 Mobile home.. 10 miles later... repeat.. but we did get that families home set up for them before Christmas.

Fortunately for air brakes the default is stop! rather than weeee! like hydro brakes.
-blizz
Rumrunner
2001 GMC 6500 3126 Cat 6spd long n low, 31' Built for the open road and to fit into 9' Garage door.

Rumrunner Website: http://351c.net/rumrunner/

#7 Budd

Budd

    Major Contributor

  • Validated Members
  • 3128 posts
  • SKP#:88936

Posted 17 January 2012 - 01:09 PM

OK, you asked so here it is: If you are talking system failure, it can happen separately to steers or to Drive wheels. On Steers, not much to notice except not stopping quite as well and a buzzer going off. On Drives with Spring Brakes, Buzzer and depending on the leak size, you will stop. Again, depending on the size of the air loss, manually holding in the Yellow button might get you a few more seconds before things lock up. My son has had this happen twice. Once crossing an overpass... he made it to the other side and off the Interstate. The other was UNDER an underpass. Again, managed to get it off the highway... but barely. The buzzer means you will stop, with or without choosing your parking spot.

But, the causes of failures can come in many flavors.

Punctured spring brake diaphragm, jammed S cam or shaft, Air leak in fittings, tubing, air canister diaphragms or other hardware including on some setups, blown air bags on axles or cab. Bad compressor or pressure governor will cause all systems to shut down.You won't move, then, for sure. A temp solution of using an external air compressor to air up will often work but will be pretty slow filling it through a schrader valve on the compressor. You won't be able to move very far on it.

Lots of choices. A worse combination, though, is a secondary failure due to some pre-existing condition, like frozen brakes or wet air supply. Setting brakes when full of ice and water can cause one to stick. Other than drag it may go unnoticed at first. Later, you may get that pretty salmon color for your rims or a lot of tire smoke... or both. This usually takes some casualties, though, and will warp/crack drums and brake shoes, damage axle seals and bearings and generally burn up or break something else, too.

Other than the brake system, other engine and drive system components may be affected, too. Air is used in some, for shifting, for controlling the turbo and sometimes, for the radiator fan so loss of air is almost always a show stopper until the cause is corrected and all collateral damage is repaired.

Air dryers can be the cause of an ongoing brake problem if it is not kept properly serviced. ANY water getting into the brake systems (that's why there are 2 air tanks between each brake system and the compressor) will begin contamination and corrosion. Rust is corrosion and valves and seals do not work for long if they are working against rusted surfaces. It also means that things, like algae and oil residues can get into these critical parts and all of these contaminants are a bitch to adequately purge from the air system. So, even on air systems with automatic purge valves, it pays to pull your drain cords occasionally and pay attention to which one/s spit out ANYthing other than clean air.

Otherwise, they are just like one would expect....they help you stop and should hold your rig when the yellow knob is out (but I have seen some that wouldn't hold.. but that is another story).

Edited by Emery Nash, 17 January 2012 - 01:15 PM.

RVBuddys Journal Our progress into full-timing.
Budd & Merrily ===-> SKP# 088936 Other Websites:---> Hub of all my blogs
Clifford - 2000 VNL64T770 :: DakotR - 1999 C40KS King of the Road :: $PRITE - 2013 Smart Passion w/cruise


#8 Bluenoser

Bluenoser

    Major Contributor

  • Validated Members
  • 604 posts
  • SKP#:104866

Posted 17 January 2012 - 03:24 PM

Great answers! Thanks. I realize that failures come in many flavors. I suspect that most folks (like me) fear the catastrophic failure that locks everything up. I did puncture an air bag last summer as well as wore a hole in hose leading to the brakes. I was very ginger with my braking until I could reach a facility to repair it. I noted a significant drop in air pressure when I braked - and used my jakes as much as I could. It all worked out.
2001 34N Pace Arrow Vision V10
2003 International 9200i 500hp ISX Freedomline 12sp
Conversion by 2L Custom Trucks
8kw QD Onan Genset/TS2BLH Hitch
Travel Supreme CL38SLQ1


Posted Image

#9 Darryl&Rita

Darryl&Rita

    Major Contributor

  • Validated Members
  • 1682 posts

Posted 17 January 2012 - 03:59 PM

Blue, don't forget that each wheel position has 2 air lines. One for park brakes, pressurized when the park brakes are released and you're rolling. The other only pressurized when you're applying the brakes to stop. This pressure is usually available on a gauge on the dash.

Veni, Vidi, Velcro
I came, I saw, I stuck around

2000 Kenworth T 2000 w/N-14 and 10 speed Gen1 Autoshift, deck built by Star Fabrication
2006 smart fourtwo cdi cabriolet
2007 32.5' Fleetwood Quantum


Please e-mail us here


#10 Jack Mayer

Jack Mayer

    Major Contributor

  • Weekend Moderators
  • 18820 posts
  • SKP#:60376

Posted 17 January 2012 - 04:16 PM

Many trucks do not have application pressure guages, so you can not count on that.....But it is "nice" to have.....another gadget....but you can certianly live without it.

Edited by Jack Mayer, 18 January 2012 - 09:50 AM.

Jack & Danielle Mayer #60376 Lifetime Member

PLEASE no PM's. Email me.
2015 New Horizons 44.5' Custom 5er; New Horizons Ambassador

2009 Volvo 780,  D16 515/1850, 230" wb, I-Shift,  custom smart hauler deck by Herrin
2012 smart Passion, piggyback on the truck
-------------------------------------------------------------------------
See our website for info on New Horizons 5th wheels, HDTs as tow vehicles, communications on the road, and use of solar power
www.jackdanmayer.com


#11 Randy retired

Randy retired

    Major Contributor

  • Validated Members
  • 976 posts

Posted 17 January 2012 - 10:28 PM

Most trucks only have park brakes on one rear axle. I have seen a few with brakes to both rear axles but never on the front axle.
Randy
2001 Volvo VNL 42 Cummins ISX Autoshift

#12 Jack Mayer

Jack Mayer

    Major Contributor

  • Weekend Moderators
  • 18820 posts
  • SKP#:60376

Posted 18 January 2012 - 09:53 AM

Randy brings up a good point. You should NOT assume that a tractor parking brake will hold your RV on a steep hill. Normally a semi-trailer has its own set of parking brakes - your RV does not , and if you have a heavy set up it can and will overcome the brakes on your tractor - on a steep incline. Chock those tires. UNLESS of course you have BluDot. In which case your trailer brakes are also engaged. All of them. Just don't leave it parked like that for days at a time.

Jack & Danielle Mayer #60376 Lifetime Member

PLEASE no PM's. Email me.
2015 New Horizons 44.5' Custom 5er; New Horizons Ambassador

2009 Volvo 780,  D16 515/1850, 230" wb, I-Shift,  custom smart hauler deck by Herrin
2012 smart Passion, piggyback on the truck
-------------------------------------------------------------------------
See our website for info on New Horizons 5th wheels, HDTs as tow vehicles, communications on the road, and use of solar power
www.jackdanmayer.com


#13 mahala

mahala

    New Member

  • All Members
  • 2 posts

Posted 12 January 2013 - 01:52 AM

I drive a school bus, and the bus I subbed on recently only has one working air pressure gauge. I discussed this with my boss when I was trained on the route, because it seems to me the brakes on this bus do not work as well as the other buses. It's her bus and she assured me that the mechanic looked at the brakes and said they were fine. But the other day when I subbed, in the dark and rain, the brakes were grabbing and the pressure on the only working gauge dropped below 100. Should be worried? The pressure later came back up, and my boss is getting angry at my concerns.

#14 Ray_nomad

Ray_nomad

    Major Contributor

  • Validated Members
  • 624 posts
  • SKP#:106256

Posted 12 January 2013 - 08:39 AM

I drive a school bus, and the bus I subbed on recently only has one working air pressure gauge. I discussed this with my boss when I was trained on the route, because it seems to me the brakes on this bus do not work as well as the other buses. It's her bus and she assured me that the mechanic looked at the brakes and said they were fine. But the other day when I subbed, in the dark and rain, the brakes were grabbing and the pressure on the only working gauge dropped below 100. Should be worried? The pressure later came back up, and my boss is getting angry at my concerns.


With all the recent concern about the schools, maybe if you mentioned (with witnesses present) that a failure with a bus full of kids due to his neglect would probably result in HIS and the bus company or county being sued and HIS probable prison term.
Ray & Deb - Shelbi the Aussie & Lexington the cat
2004 Volvo 630 500HP ISX "Bertha D" - 10 Speed-MaxBrake -ET hitch.
Pressure Pro (since the blowout)
2009 Designer 35RLSA
Fulltiming since '07

#15 Leadfoot

Leadfoot

    Major Contributor

  • Validated Members
  • 672 posts

Posted 12 January 2013 - 02:28 PM

I drive a school bus, and the bus I subbed on recently only has one working air pressure gauge. I discussed this with my boss when I was trained on the route, because it seems to me the brakes on this bus do not work as well as the other buses. It's her bus and she assured me that the mechanic looked at the brakes and said they were fine. But the other day when I subbed, in the dark and rain, the brakes were grabbing and the pressure on the only working gauge dropped below 100. Should be worried? The pressure later came back up, and my boss is getting angry at my concerns.


Hmmmmm - you also started a thread looking for comments on driving schools.

IM0 - unless you really, really need that substitute school bus driver job......I would go a step further than ray nomad suggests, put your "findings" in writing (for a "CYA") -
while you're looking for a different employer (or a different part time job) . The latter suggestion would rate a - sooner than - "ASAP".

If that route (no pun intended) doesn't appeal to you . . . . .

Try your question & concerns to a LEO at a weigh station - or ask at your local PD who does commercial enforcement, and ask him/her for their "thoughts & opinions".

Maybe some of the resident "pros" on here will chime in too.

And....FYI - *Liability* can extend to....you!

.

Edited by Leadfoot, 12 January 2013 - 03:19 PM.


#16 Pete K

Pete K

    Senior Member

  • Validated Members
  • 443 posts

Posted 12 January 2013 - 05:28 PM

I drive a school bus, and the bus I subbed on recently only has one working air pressure gauge. I discussed this with my boss when I was trained on the route, because it seems to me the brakes on this bus do not work as well as the other buses. It's her bus and she assured me that the mechanic looked at the brakes and said they were fine. But the other day when I subbed, in the dark and rain, the brakes were grabbing and the pressure on the only working gauge dropped below 100. Should be worried? The pressure later came back up, and my boss is getting angry at my concerns.


Go over there heads on this one. No reason to put your life and a bus load of kids life's in danger on someone's word that does not know what she is talking about. Everything should work on that bus. Not just part of it. My dad used to drive a bus, he had issues with one bus. They told him it was ok. Well that evening he found Tn DOT set up checking log trucks on the way home. They laughed at him for pulling over. But after telling them what was up, they shut the bus down. Wrote of the county and did a surprise inspection on every bus. 40% of them failed. 2 people lost there jobs over it. But the kids were safe after that, and Dad had lots of people thanking him for standing up for it also.Posted Image

Pete

2005 Chevy Kodiak c5500 Cummins powered Allison tran's.

5500-02.jpg


#17 Bob Cochran

Bob Cochran

    Major Contributor

  • Validated Members
  • 2128 posts
  • SKP#:105438

Posted 12 January 2013 - 07:47 PM

Absolutely do not put yourself or those kids in danger. Do any/all the suggestions above. If anything should happen or happen should you choose to leave their employee can you life with that? Also if something should happen it puts you as culpable as them. I personally could not but that is me. :)

Own a 37 foot 2014 Keystone Fuzion pulling with 1998 Freightliner Century. Fortunate to retire early intending to full time but circumstances prevents this at the present time. Living in a sticks and bricks home all paid off DW has to have roots some place and this works.


#18 trucksaledave

trucksaledave

    Major Contributor

  • Validated Members
  • 903 posts
  • SKP#:96553

Posted 12 January 2013 - 08:23 PM

Many...many years ago I had a road tractor's brake foot valve lock up at 40 mph. I was coming up to a stop sign. The only thing to do was pull out the PTV tractor protection valve.....It was not pretty...but I stopped.

The very first thing a DOT man checks when he pulls over a truck for a inspection is check for the low air buzzer. The truck has to be fixed on site or towed.

When I park my HDT anytime. I always chock my tires and leave the transmission in first gear.

Dave
2001 IHC 9200i....."WEEKEND WARRIOR"
Single axle...N-14 cummins...super10...jake...72" sleeper/sofa...shore power...
2007 SunnyBrook 38'
and... one very large Maine Coon CAT.....SAMANTHA

My toys....www.picturetrail.com...trucksaledave

#19 Big5er

Big5er

    Major Contributor

  • Validated Members
  • 820 posts

Posted 13 January 2013 - 11:12 AM

Go over there heads on this one. No reason to put your life and a bus load of kids life's in danger on someone's word that does not know what she is talking about. Everything should work on that bus. Not just part of it. My dad used to drive a bus, he had issues with one bus. They told him it was ok. Well that evening he found Tn DOT set up checking log trucks on the way home. They laughed at him for pulling over. But after telling them what was up, they shut the bus down. Wrote of the county and did a surprise inspection on every bus. 40% of them failed. 2 people lost there jobs over it. But the kids were safe after that, and Dad had lots of people thanking him for standing up for it also.Posted Image

Pete


The DOT can't just walk onto a business (or school) parking lot and just start inspecting their vehicles without permission, and as dumb as it sounds, school buses (whether publicly or privately owned) are exempt from the Fed Regs (except cell phone usage and texting) during "School Bus Operation" which means transporting school kids and/or employees from "home to school" and "school to home". So technically you are right, everything SHOULD work on that bus, but nothing HAS to work on that bus (now, ain't that stupid?). Now, if you drive a totally empty school bus into a a check point that might work but other than catching each and every school bus totally empty or traveling somewhere other than home and school (ie: after school activities), they cant shut a school bus down or even ticket it for a violation of the FMCSA rules. And the DOT doesn't "write up the county", they write up an inspection which shows who the owner is, but the driver is the one that gets the tickets. Now hopefully the school bus owner will do the right thing and step up to pay the fine, but the points and violations still go on the drivers record which could affect his employment if the school district has a policy about an employees driving record.

Already fulltiming, but......

 


#20 Leadfoot

Leadfoot

    Major Contributor

  • Validated Members
  • 672 posts

Posted 13 January 2013 - 01:17 PM

Hmmmmm - you also started a thread looking for comments on driving schools.

IM0 - unless you really, really need that substitute school bus driver job......I would go a step further than ray nomad suggests, put your "findings" in writing (for a "CYA") -
while you're looking for a different employer (or a different part time job) . The latter suggestion would rate a - sooner than - "ASAP".

If that route (no pun intended) doesn't appeal to you . . . . .

Try your question & concerns to a LEO at a weigh station - or ask at your local PD who does commercial enforcement, and ask him/her for their "thoughts & opinions".

Maybe some of the resident "pros" on here will chime in too.

And....FYI - *Liability* can extend to....you!

.


Kinda veered off track with the "Gee Whiz" stuff...:blink:

My thoughts on ASKING (at a scales, or the local PD) were simply some convenient places to solicit some OPINIONS.

*NOT*
suggesting to do so WITH (while driving) the bus!

Same for comments from the resident "pros" - - - suggestions on how to handle the "situation" the part time bus driver has encountered.

(Or maybe, just ignore it with a cheerful - - - "Hi-ya nose pickers!")

.